Section 3-406. Leases for public purposes

All applications to lease any real
  property  for  the  purposes of the city or any of the counties therein,
  including the premises required in accordance with law for armories  and
  drill rooms and places of deposit for the safekeeping of arms, uniforms,
  equipment,  accoutrements  and camp equipage of the national guard, must
  be presented to and passed upon by the board  of  estimate.  The  board,
  upon  the  report of the commissioner of general services, and upon such
  further inquiry  as  such  board,  in  its  discretion,  may  make,  may
  authorize  a  lease  of  such  premises  as  shall  be  specified in its
  resolution, at the rent therein set forth for  a  period  not  exceeding
  twenty-one  years.  Such  lease  may  contain  a  provision for renewals
  thereof at the option of the city. Such lease,  however,  shall  not  be
  authorized except at a fair and reasonable rent, and unless the board is
  satisfied,  and  shall  so express, that it would be for the interest of
  the city that a lease of the premises for the purposes specified  should
  be  made.  If  the  city,  prior  to the making of the lease, shall have
  entered upon the possession of the property, the lease may  be  made  to
  commence as of the date when the occupation commenced.